Process for the preparation of 2-(5-isopropyl-5-methyl-4-oxo-2-imidazolin-2-yl)-3-quinoline-carboxylic acid and alkyl 2-trichloromethyl-3-quinoline-carboxylate intermediates therefor

Abstract

The invention is related to a novel process for the prepartion of 2-(5-isopropyl-5-methyl-4-oxo-2-imidazolin-2-yl)-3-quinolinecarboxylic acid, a useful and valuable herbicide.

We claim: 
     
       1. A process for the preparation of a compound of formula ##STR4## comprising reacting one molar equivalent of a compound of formula ##STR5## wherein R is C 1  -C 3  alkyl with from one molar equivalent to two molar equivalents of 2-amino-2,3-dimethylbutyramide; in the presence of an inert solvent of benzene, toluene or xylene; and from 3 molar equivalents to 5 molar equivalents of anhydrous sodium or potassium hydroxide; 2 molar equivalents of anhydrous sodium or potassium carbonate, and from 0.1 molar equivalent to 0.3 molar equivalent of a phase transfer catalyst of tetra(C 3  -C 6 )alkylammonium salts, benzyltri(C 1  -C 6 )alkylammonium salts, crown ethers or tetraalkylphosphonium salts; from 80° C. to 130° C. or at the atmospheric boiling point of the solvent for a period of time sufficient to essentially complete the reaction. 
     
     
       2. A process according to claim 1, wherein the amount of 2-amino-2,3-dimethylbutyramide is one molar equivalent; the solvent is toluene; the amount of sodium hydroxide is 3.3 molar equivalents; the amount of potassium carbonate is two molar equivalents; the phase transfer catalyst is tetrabutylammonium hydrogen sulfate used in a 0.1 molar equivalent amount; and the temperature of the reaction is the atmospheric boiling point of toluene. 
     
     
       3. A compound of the formula: ##STR6## wherein R is C 1  -C 3  alkyl. 
     
     
       4. A compound according to claim 3, ethyl 2-trichloromethyl-3-quinolinecarboxylate.